ActiGraph Objective Measures

The ActiGraph GT9X Link captures and records high resolution raw acceleration data, which is converted into a variety of objective activity and sleep measures using publicly available algorithms developed and validated by members of the academic research community. Available measures include:

ActiGraph Link Features

Programmable Display

The ActiGraph GT9X Link features a programmable LCD window that can be configured to display date and time and/or provide real-time activity feedback such as steps and kcals, or it can be completely disabled.

Inertial Measurement Unit (IMU)

An integrated IMU containing a gyroscope, magnetometer, and secondary 3-axis accelerometer sensors provides raw position and rotational data for a variety of advanced applications, including inclination, gait analysis, and fall detection.*

Bluetooth® Smart

The ActiGraph GT9X Link is powered by Bluetooth® Smart technology and offers a variety of wireless features, including heart rate monitoring, proximity detection, and communication with ActiGraph’s suite of mobile applications for iOs and Android devices.

Wear Time Sensor

An advanced wear time sensor on the back of the device uses capacitive touch technology to automatically detect when a wrist worn device has been removed for simplified compliance monitoring and data cleaning.

* ActiGraph products are not intended to diagnose, treat, cure, or prevent any disease.

The accelerometer measures acceleration normalized to Earth gravity (g). The gyroscope measures angular rates in degrees per second. The magnetometer measure magnetic field strength in microteslas. The thermometer measures temperature of the IMU in Celsius.

Variations in magnetic north versus true north vary by location in a predictable way. There are lookup tables available. The magnetic field measurements may also be affected by hard and soft iron effects.